I have my GT S6102 bought last year. I wonder why its battery drains up easily - a matter of minutes. Then while it functions, the unit is going hot and hot.It even drains up its battery even the unit is turned off. Tell me why?

Me using Samsung y duos. But from last 2 weeks my mobile not vibrating for incoming msgs., but it vibrate for incoming calls. Don't know why! Because of this reason I can't identify the msgs when my mobile in silent mode.lease help me ? mai me soon.